Carton



R. W. GRIESE July 27, 1965 CARTON 3 Sheets-Sheet 1 Original Filed May17, 1957 Fig./

INVENTOR. ROBERT w. GRIESE BY W fi Fig. 2

ATTORNEYS R. W. GRIESE July 27, 1965 CARTON 3 Sheets-Sheet 2 0 Fig. 4

Original Filed May 17, 1957 0 Fig. 3

INVEN TOR. ROBERT W. GRIESE BY @[M ATTORNEY United States, Patent3,197,113 CARTON Robert W. Griese, Topeka, Kans., assignor, by vinesneassignments, to American Can Company, New York, N .Y., a corporation ofNew Jersey Continuation of application Ser. No. 659,918, May 17, 1957.This application Oct. 31, 1962, Ser. No. 234,907 1 Claim. (Cl. 229-49)This application is a continuation of application Serial No. 659,918,filed May 17, 1957, now abandoned.

This invention relates to a carton construction having opposed parallelwalls and provided internally with a flexible strut or bridge adhered totwo opposed walls in order to restrain such walls from bowing or bulgingoutwardly when the carton is filled with any materials to be packagedtherein.

Further details and advantages of the invention will be apparent fromthe following description and accompanying drawings, wherein FIGURE 1 isa plan view of a cardboard blank suitably scord and cut for making acarton construction according to the present invention,

FIGURE 2 is a plan view of the blank shown in FIG- URE 1 having asuitable flexible strut applied and adhered thereto, 7

FIGURE 3 is a plan view of the blank and strut assembly shown in FIGURE2 and in folded condition for forming a carton,

FIGURE 4 is a further stage of the assembly in making a cartontherefrom,

FIGURE 5 is a perspective view of a carton formed from the folded andglued blank shown in FIGURE 4, having its upper end open for receivingcontents therein to be packaged,

FIGURE 6 is a sectional view taken on lines 66 of FIGURE 5.

FIGURE 7 is a schematic representation of a crosssection taken on lines77 of FIGURE 4, and

FIGURE 8 is a schematic representation similar to FIGURE 6.

Referring to the drawings, the carton preferably is made from a singleblank of suitable flexible sheet material, such as cardboard, metalfoil, plastic sheet materials, and the like of desired thickness anddimensions. The blank is suitably scored along lines indicated bynumerals 1 to 8, and cut along lines 9, 1t and 11, as shown in FIGURE 1to provide end walls or panels 12 and 14, side walls or panels 13 and15, respectively, and end flaps 17, 19, 20 and 21 hinged to theaforementioned walls 12 to 15, respectively. The respective panels areadapted to be positioned in substantially parallel relationship, asshown in FIGURE 5 in the completed setupcarton. The respective pairs ofwalls are also preferably of substantially the same dimensions. Gluepanel 16 is adapted to be adhered to overlapped portion of end wall 12,as shown in FIGURE 6 to provide a tubular carton of rectangularcross-section.

In forming a carton from the blank shown in FIGURE 1 and simultaneouslyproviding a flexible strut or bridge within the carton, the followingprocedure may be carried out. Glue areas 35 and 36 of suitable area anddimensions are applied to panels 13 and 14, as shown in FIGURE 1. Theseglue areas are preferably positioned at approximately the medialportions of panels 13 and 15. A flexible strip 30, made of suitablematerial, such as paper, cellophane, glassine, and the like of suitabledimensions is then positioned on panel 13 and one end 25 thereof isadhered to the glue area 35. Panel 15 is then folded along score line 3so as to overlie panel 13 as shown in FIGURE 3. The end 26 of strip 39will at the same time become adhered to glue area 36 on in connectionwith FIGURE 4.

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panel 15. Adhesive is then applied to glue panel 16 and panel 12 is thenfolded thereon as shown in FIGURE 4. The glued blank is then set up andthe bottom closure is formed by folding flaps 17 and 20 inwardly,folding flap 19 thereover, and then folding over flap 21 and adheringsame to the flaps underneath in any suitable man ner.

The resulting structure is shown in FIGURE 5, the inner flexible strip30 extending between side Walls 13 and 15. As previously indicated, thisinvention involves a carton with opposed pairs of parallel side walls,and the walls of one pair are intended to be perpendicular to the otherpair. Under such conditions, it is clear that in the usual case it willbe desirable for maximum effectiveness to locate the, strut in themid-portion of'the carton, or perhaps slightly below in order to accountfor settling of the contained product. However, the strut of course maybe located at any desired part of the carton. In the usual situation,italso will be desirable to locate the strut perpendicular to the wallsto whichit is attached and of length equal to the spacing between thosewalls along their lateral edges. However, by adjusting the location ofglue areas 35 and 36, and coordinating the effective unadhered length30a of strut 30 therewith, the strut may be accommodated to either pullthe side walls of the carton inwardly or to let the side walls bulgeoutwardly, as will be described later.

After the carton is filled with any suitable commodity to be packagedtherein the end flaps 17 and 20 are folded inwardly and the closureflaps 19 and 21 are folded over and suitably adhered to sealthe carton.The flexible strut 31) within the carton will prevent the opposed walls13 and 15 of the carton from bulging outwardly, especial- 1y when denseor heavy materials are packaged in the cartons. When cartons 'of fairlylarge size are used, such as for packaging supersize granulateddetergents, which may have parallel front and rear panels measuring say10 x 16 inches, there is a pronounced tendency for these panels to bulgeoutwardly and thus present an unsightly appearance. The provision of aninternal flexible strut or bridge in accordance with this invention willprevent such undesirable bulging and will maintain the package in propershape without bulging walls.

The carton provided with the internal strut maybe made with anysuitable, equipment and any suitable SC? quence of steps may be followedin positioning and adhering the flexible strut Strip between two opposedparallel walls of the carton. One method has been previously described.Another method, using a similar blank as shown in FIGURE 1, canbefollowed by first prebreaking score line 4 on which glue flap 16 ishinged. Adhesive is then applied to areas 35 and 36. One end of flexiblestrut strip 30 is then attached to glue area 36. Score line 3 isprebroken and adhesive is applied to the reverse face of glue flap 16shown in FIGURE 1. Panel 15 is-then folded overon panel 13. Panel 12 isthen folded over on glue panel 16 whereby the glued lank as shown inFIGURE4 is produced. FIGURE 7 is a schematic cross-section of the cartonin the condition shown in FIGURE '4, the unadhered portion Stla of strut30. being hinged to the side walls at x and y. Hinge lines at and y arerespectively spaced from end wall 14 by distances a and c, and the sideand end walls are respectively of dimensions d and b. FIG.- URE 7 showsthe carton extended slightly towardthe open position, but this is solelyfor purposes of illustration, and in the following discussion it isassumed that the carton is in the completely fiat shape as described Itis clear from FIGURES 1 and 7 that if glue areas 35 and 36 are solocated that distance a is equal to distance c then the strut will inthe erected condition of V r 3 the carton as shown in FIGURE 5 lieperpendicular to Walls 13 and -155Further, if there'were no folds instrut 30, its length in the carton-erected position of FIGURE 5 will beprecisely equal to the lateral dimension of end Walls 121and'14, and thestrut willassist in maintenance of a carton of parallelogramcross-section.

'It is also clear that if glue areas 35 and 36 are located so that informing the carton (FIGURE 7) distance a is greater than distance 0, thestrut will be of length greater than the distance between x and y in therectangular formationfof the carton as shown in FIGURE 5, and the strutwill permit the carton to bulge beyond a rectangular cross-section.Conversely, if the distance a is less than distance c, strut 30a inerected condition will be of length less than the lateral dimension ofthe end walls, and the strut will consequently pull the side wallsinwardly when the carton is erected.

Applicant has discovered that there are certain limitations on thepositioning of the glue areas 35 and 36. Referring also to FIGURE 8, itis apparent that the lateral displacement e. between hinge lines x and ymust, in the carton-erected condition, never exceed the length of strut30. This conclusion results from the fact that the strut must span thecombination of the displacement e and the displacement between the hingelines perpendicular to e, so clearly e alone can never equal the lengthof the strut.

elength of strut 30 means equal to or less than length of strut 30=a+b-c(see FIGURE 7) From which:

c-aa-l-b-c That is:

Zmeans equal to or greater than j the carton, although its limit ofpractical utility would Referring to FIG- be reached at a much earlierstage. URE 7, we see that the theoretical limit on length of a usefulstrut occurs when its length becomes as great as the diameter of acircle the circumference of which is equal tothe perimeter of thecarton. Thus:

length of strut 30=a+bc a+b-c diameter of a circle the circumference ofwhich is 2b+2d It will be clear that in the above description concerningFIGURES 7 and 8, references to strut 30 are intended to mean theeffective connecting (unadhered) portion 30a.

It is to be understood that the invention is not restricted to anyspecific type of cartonconstruction and that the internal strut orbridge may be suitably applied to any type of carton construction inwhich the opposed walls may have a tendency to bulge outwardly. It isobvious that the internal strut may be positioned internally of thecarton at any suitable location to prevent bulging of the opposed wallsand that the dimensions of the flexible strut may be varied dependingupon the overall size of the carton. While in most usages the cartonmust be constructed of a fairly heavy paperboard or like material, thestrut may be formed from a very light paper or film, since it is subjectonly to tension forces, thus keeping at aminimum the cost of the entirecarton. As is clearly illustrated in V the drawings, particularlyFIGURES 1 through 5, strut 30 has relatively a very small dimensionalong the height of the carton, that is, parallel to the longerdimension of walls 12 to 15, so that the strut in no wise formsapartition in or provides a division of the carton, but rather presentsessentially no barrier to movement of contained material from any partof the carton to any other part, regardless of the attitude or degree offill of the carton. The internal strut should of" course have sufficientstrength to withstand rupturing upon being stressed by any outwardbulging of the carton panels to which it is attached. Also the strutshould be adequately adhered over a sufficient area to resist beingdetached from the surfaces to which it is connected. In some instancesthe flexible strut may be reinforced with flexible threads or wires. Itmay also be made of woven textile materials, such as cellulosic films,nylon, Dacron, glass fibers and the like. It will be obvious that strut30, having been referred to as a strip, will have significant dimensionsof height and length, that is, parallel to the respective walls 12 to15, but will have a relatively insignificant. third dimension ofthickness. Strut 30 is, then, as set forth herein, a strip or Web ofmaterial of light weight relative to the principal carton formingmaterial. It will be clear to those skilled in the art that reference tostrut 30 as being very light or of relatively light weight material isin terms of basis weight, that is, weight per unit of area, for example,weight per ream of the web or strip of material of which strut 30 isformed.

I claim:

A reinforced rectangular collapsible carton formed of paperboard andadapted for packing materials which tend to settle in said carton and tobulge the walls thereof outwardly comprising a pair of opposed flexibleside walls, a pair of opposed end walls, top and bottom closures, and aneasily foldable flexible substantially rectangular reinforcing struthaving surface portions thereof adjacent its ends adhesively connectedto opposed medial areas of said side walls, said portions of said strutbeing adheredover a sufiicient area to resist being detached from theadjacent side walls when the carton is set up, the unadhered surfaceportions of said strut being adapted to be in face-toface contact withthe adjacent collapsed side walls and permitting .free erection of thecarton from collapsed.

to rectangular shell form, said strut consisting of a strip of sheetmaterial separate from said walls and of substantially lighter basisweight than the paperboard of the carton, said strut being of lengthless than the diameter of a circle the circumference of which equals thecombined Widths of said walls, said strut being substantially spacedfrom all free edges of all of said walls and in its dimension parallelto the planes of said walls being of relatively small magnitude comparedto the length of the walls whereby said strut is spaced from the saidtop and bottom closures so as to permit the materials packaged in saidcarton to intermingle freely, said strut serving to prevent outwardbulging of the opposed walls connected thereto when the materialspackaged in said carton tend to settle therein.

References Cited by the Examiner UNITED STATES PATENTS Re. 24,789 3 60Pasjack 220- 2,03 6,987 4/36 Watson 229-6 2,673,022 3 5 4 Prossen 20646THERON E. CONDON, Primary Examiner.

EARLE J. DRUMMOND, GEORGE O. RALSTON,

Examiners.

